feat: replace Decord with video_reader-rs

python/pyproject.toml

@@ -21,6 +21,7 @@ runtime_common = [
     "build",
     "compressed-tensors",
     "datasets",
+    "video-reader-rs",
     "fastapi",
     "hf_transfer",
     "huggingface_hub",

python/sglang/check_env.py

@@ -47,7 +47,7 @@ def is_cuda_v2():
     "tiktoken",
     "anthropic",
     "litellm",
-    "decord",
+    "video-reader-rs",
 ]
 
 

python/sglang/srt/multimodal/processors/base_processor.py

@@ -12,7 +12,6 @@
 import torch
 from PIL import Image
 from transformers import BaseImageProcessorFast
-
 from sglang.srt.managers.schedule_batch import Modality, MultimodalDataItem
 from sglang.srt.utils import load_audio, load_image, load_video, logger
 
@@ -206,7 +205,7 @@ def get_estimated_frames_list(self, image_data):
         estimate the total frame count from all visual input
         """
         # Lazy import because decord is not available on some arm platforms.
-        from decord import VideoReader, cpu
+        from video_reader import PyVideoReader, cpu
 
         # Before processing inputs
         if not image_data or len(image_data) == 0:
@@ -216,7 +215,7 @@ def get_estimated_frames_list(self, image_data):
             if isinstance(image, str) and image.startswith("video:"):
                 path = image[len("video:") :]
                 # Estimate frames for the video
-                vr = VideoReader(path, ctx=cpu(0))
+                vr = PyVideoReader(path, threads=0)
                 num_frames = len(vr)
             else:
                 # For images, each contributes one frame

python/sglang/srt/utils.py

@@ -74,6 +74,7 @@
 import torch.distributed as dist
 import triton
 import zmq
+from video_reader import PyVideoReader
 from fastapi.responses import ORJSONResponse
 from packaging import version as pkg_version
 from PIL import Image
@@ -757,24 +758,16 @@ def load_image(
 
 def load_video(video_file: Union[str, bytes], use_gpu: bool = True):
     # We import decord here to avoid a strange Segmentation fault (core dumped) issue.
-    from decord import VideoReader, cpu, gpu
-
-    try:
-        from decord.bridge import decord_bridge
-
-        ctx = gpu(0)
-        _ = decord_bridge.get_ctx_device(ctx)
-    except Exception:
-        ctx = cpu(0)
-
+    from video_reader import PyVideoReader
+    device = 'cuda' if use_gpu and torch.cuda.is_available() else None
     tmp_file = None
     vr = None
     try:
         if isinstance(video_file, bytes):
             tmp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".mp4")
             tmp_file.write(video_file)
             tmp_file.close()
-            vr = VideoReader(tmp_file.name, ctx=ctx)
+            vr = PyVideoReader(tmp_file.name, device=device, threads=0)
         elif isinstance(video_file, str):
             if video_file.startswith(("http://", "https://")):
                 timeout = int(os.getenv("REQUEST_TIMEOUT", "10"))
@@ -784,22 +777,22 @@ def load_video(video_file: Union[str, bytes], use_gpu: bool = True):
                 for chunk in response.iter_content(chunk_size=8192):
                     tmp_file.write(chunk)
                 tmp_file.close()
-                vr = VideoReader(tmp_file.name, ctx=ctx)
+                vr = PyVideoReader(tmp_file.name, device=device, threads=0)
             elif video_file.startswith("data:"):
                 _, encoded = video_file.split(",", 1)
                 video_bytes = base64.b64decode(encoded)
                 tmp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".mp4")
                 tmp_file.write(video_bytes)
                 tmp_file.close()
-                vr = VideoReader(tmp_file.name, ctx=ctx)
+                vr = PyVideoReader(tmp_file.name, device=device, threads=0)
             elif os.path.isfile(video_file):
-                vr = VideoReader(video_file, ctx=ctx)
+                vr = PyVideoReader(video_file, device=device, threads=0)
             else:
                 video_bytes = base64.b64decode(video_file)
                 tmp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".mp4")
                 tmp_file.write(video_bytes)
                 tmp_file.close()
-                vr = VideoReader(tmp_file.name, ctx=ctx)
+                vr = PyVideoReader(tmp_file.name, device=device, threads=0)
         else:
             raise ValueError(f"Unsupported video input type: {type(video_file)}")